Documentation: cpu-hotplug: Fix sysfs mount instructions

The instructions for mounting sysfs are inconsistent in instructing to
create the directory '/sysfs' but then mounting sysfs to /sys.
Also, indentation is slightly off.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/cpu-hotplug.txt

@@ -150,7 +150,7 @@ an entry as shown below in the output.
 
 If this is not mounted, do the following.
 
-	 #mkdir /sysfs
+	#mkdir /sys
 	#mount -t sysfs sys /sys
 
 Now you should see entries for all present cpu, the following is an example